The present invention relates to an airbag apparatus that deploys and inflates an airbag in front of an occupant seated on a seat of a vehicle to protect the occupant from an impact applied to the vehicle in front of the seat.
An airbag apparatus is effective for protecting an occupant from an impact applied to the automobile, for example, during a collision. For example, U.S. Pat. No. 9,308,883 and US Patent Application Publication No. 2016/0107598 each disclose one type of an airbag apparatus that protects an occupant seated in a rear seat from an impact. The airbag apparatus includes an airbag and an inflator, which are accommodated in a housing located in the seatback of a front seat. The airbag includes two regular inflation portions, which are arranged next to each other from the housing toward the rear seat, and a connecting inflation portion, which connects upper ends of the two regular inflation portions to each other.
With the above airbag apparatus, when an impact is applied to the automobile from the front, the inflator supplies inflating gas to the front regular inflation portion in response to the impact. After passing through the front regular inflation portion, the inflating gas flows to the connecting inflation portion and the rear regular inflation portion. The inflating gas sequentially deploys and inflates the front regular inflation portion, the connecting inflation portion, and the rear regular inflation portion from the housing toward the rear seat.
When an impact is applied to the automobile from the front, the automobile stops. However, the upper body of the occupant, which is constrained by a seatbelt apparatus, will be forced diagonally forward by inertia. However, the airbag deploys and inflates in front of the occupant and receives the upper body of the occupant. This constrains the upper body of the occupant so that the upper body remains at the same position.
With the above prior art airbag apparatus, when the airbag deploys and inflates, the rear regular inflation portion, which directly receives the load of the upper body of the occupant that is forced diagonally forward, is separated toward the rear and distant from the front regular inflation portion, which is supported by the housing. This forms a large gap in the front-rear direction between the two regular inflation portions. When the rear regular inflation portion receives the load of the upper body of the occupant, which is forced diagonally forward, the rear regular inflation portion is deformed toward the front. There is no restriction that limits the forward deformation of the rear regular inflation portion. In this manner, the airbag constrains the occupant as the rear regular inflation portion greatly deforms forward when receiving the load of the upper body of the occupant. With the above prior art airbag apparatus, the occupant is practically constrained by only the rear regular inflation portion. Therefore, there is room for improvement for achieving appropriate constraint.